Oldsport,
Re: Surly Big Dummy and Yuba Mundo
I have both, a Big Dummy and Mundo... for a shared cargo bike, the Mundo is my first choice. As my personal bike and primary transportation, the Big Dummy is the only choice. I like the Mundo for heavier loads (70 pounds plus) and Big Dummy for lighter loads. Both bikes are used for recreational riding, the Big Dummy is my ride. (Big Dummy is my touring bike.) Wife is 5'8" and I'm 6'0" so sharing the Mundo is easy, the upright riding position of Mundo also helps with one-size-fits-all.
Either bike is a good choice... but the Big Dummy provides that something-special feel for me. (Mundo is still a fun ride.)